Unity splitting up terrains into equal heightmap resolution ones.

Hey!

So I have bit of an issue here. I am working on about a 20000 x 20000 terrain, and the heightmap resolution is 2049 (which of course causes the brushes to be huge in contrast to detail models). What i want to do is "slice" up the terrain into smaller parts, but the goal is that those smaller terrains would keep their resolution of 2049. I already tried a Terrain Slicing asset, but it sliced the terrain up into 513 heightmap res terrains, which didnt really make the brushes small enough for detailing the terrain. I really need help in this.